Brain tumor detection and segmentation have been of interest to researchers, however, no robust, automated algorithm has been adopted in the clinical setting. Tumors may be malignant or benign as determined by a biopsy, and are known to affect brain symmetry and cause damage to the surrounding brain tissues. In particular, Glioblastoma Multiforme (GBM) is a very common and dangerous malignant primary brain tumor, for example. These tumors are characterized by jagged boundaries with a ring enhancement, possibly a dark core necrotic component, and are accompanied by edema (swelling).
Automated approaches to segment these types of tumors can be challenged by the variability in size, shape and location of the tumor, the high degree of similarity in the pixel intensities between normal and abnormal brain tissue regions, and the intensity variations among identical tissues across volumes. As a result, unsupervised thresholding techniques have not been very successful in accurate tumor segmentation. Furthermore, approaches that incorporate prior knowledge of the normal brain from atlases require accurate non-rigid registration, and hence, generating adequate segmentation results potentially calls for user-intervention and/or a patient specific training system. In addition, these methods can require elaborate preprocessing, and they tend to overestimate the tumor volume. The Chan-Vese active contour method is a widely adopted approach that is usually combined with a level-set evolution for convergence to a region of interest. Though this method is robust to noise in the image, and can work reasonably well even with blurred images, it requires a reliable initial estimate to be provided by the user. Furthermore, the high computational cost of this method preempts its use in a large-scale setting.
For simplicity and clarity of illustration, the drawing figures herein illustrate the general manner of construction, and descriptions and details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the invention. Additionally, elements in the drawing figures are not necessarily drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of embodiments of the present invention. The same reference numerals in different figures denote the same elements.
The terms “first,” “second,” “third,” “fourth,” and the like in the description and in the claims, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms “include,” and “have,” and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, device, or apparatus that comprises a list of elements is not necessarily limited to those elements, but may include other elements not expressly listed or inherent to such process, method, system, article, device, or apparatus.
The terms “left,” “right,” “front,” “back,” “top,” “bottom,” “over,” “under,” and the like in the description and in the claims, if any, are used for descriptive purposes and not necessarily for describing permanent relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the invention described herein are, for example, capable of operation in other orientations than those illustrated or otherwise described herein.
The terms “couple,” “coupled,” “couples,” “coupling,” and the like should be broadly understood and refer to connecting two or more elements or signals, electrically, mechanically or otherwise. Two or more electrical elements may be electrically coupled, but not mechanically or otherwise coupled; two or more mechanical elements may be mechanically coupled, but not electrically or otherwise coupled; two or more electrical elements may be mechanically coupled, but not electrically or otherwise coupled. Coupling (whether mechanical, electrical, or otherwise) may be for any length of time, e.g., permanent or semi permanent or only for an instant.
“Electrical coupling” and the like should be broadly understood and include coupling involving any electrical signal, whether a power signal, a data signal, and/or other types or combinations of electrical signals. “Mechanical coupling” and the like should be broadly understood and include mechanical coupling of all types. The absence of the word “removably,” “removable,” and the like near the word “coupled,” and the like does not mean that the coupling, etc. in question is or is not removable.